As the copper (Cu) interconnection size scales down, the step coverage and overhang of the physical vapor deposition (PVD) barrier is becoming worse for the 0.1 μm generation and beyond, especially with deep vias and trenches.
U.S. Pat. No. 6,197,688 B1 to Simpson describes a palladium-tin (Pb—Sn) catalyst layer 31 for a copper (Cu) electroless deposition.
U.S. Pat. No. 6,022,808 to Nogami et al. describes an electroless Cu deposition with improved electromigration by forming a Sn-doped Cu layer over a Cu layer.
U.S. Pat. No. 6,147,000 to You et al. describes an electroless Cu deposition with improved electromigration by diffusing Sn into a Cu layer.
U.S. Pat. No. 6,268,291 B1 to Andricacos et al. describes an electroless Cu deposition with improved electromigration by implanting Sn into a Cu layer.
U.S. Pat. No. 6,162,667 to Funai et al. describes a method for fabricating thin film transistors that is related to the instant invention.